This invention relates to a rotary drum, used in the casting field, and having major application for the treatment of mold sand, as to achieve its reclaiming, cooling, blending, or separation from the castings, but in this particular instance, incorporates hood means having predesigned passages for diverting air around the approximate discharge end of the drum, for the elimination of dust and sand fines that accumulate thereat, for their discharge and collection or disposal.
There are a variety of prior patents that have been obtained upon various style of rotary drums for use in the casting industry. For example, one of the early embodiments is that which is shown in the U.S. Pat. No. 3,998,262, to Charles J. Didion, the inventor of the development described herein, showing a casting shake-out unit and method of operation. Essentially, such a drum is arranged upon its structural support, rotated by means of drive means, so that when castings clogged with mold sand as directly obtained from the site of their casting, are then passed through the shown rotary drum, the mold sand is effectively separated and removed from the prepared castings, to achieve the required separation without necessitating the employment of any labor to attain such results.
In addition, another patent to Charles J. Didion, U.S. Pat. No. 4,674,691, shows a related type of rotary drum, of the type used for sand reclaiming, wherein the type of sand removed by the apparatus as shown in the U.S. Pat. No. 3,998,262, is further processed, separated, all in preparation for its reusage in the casting industry. In any event, and regardless which rotary type drum may be employed for achieving their intended results, as described in said patents, there is always the associated problem with the generation of excessive dust, and sand fines, that have a tendency to enter into the air stream, and need to be removed in order to adequately assure the safety and health of the worker, and also to comply with various government regulations.
The usage of shrouds or hoods around the discharge end of a drum has been employed in the prior art, as can be seen in the U.S. Pat. No. 4,050,635, to Mueller, et al, wherein the shown housing incorporates an outlet chute, at its lower end, for attaining the discharge of the castings, or its sand, therefrom, during operations of the shown device. In addition, such hoods have been used for collection and removal of sand particles, to facilitate the collection of the sand in preparation for its reusage. But, the usage of a ventilating hood, which has various ventilating ports designed therein so as to accommodate the flow of air around and through the discharge end of the rotary drum, for the removal of heat from sand and containment of fines and dust, while likewise diverting the separated mold sand for passage to a discharge opening, as arranged at the bottom of the ventilating hood, apparently has not been done previously.